php $_files 不断上传

Question

我有一个脚本执行一些简单的编辑，效果很好，问题是即使图像上传成功并且我刷新页面，即使没有从表单提交时的文件输入中选择它，也会创建相同的图像：

<form  method="post"  enctype="multipart/form-data" id="<?php echo $_SERVER['PHP_SELF']; ?>">
                     <fieldset id="product-images">
                    <input type="file" id="image" name="image" />
                    <input type="submit" name="picture" value="upload Picture"/>
</form>

这是 php

 <?php if(isset($_POST['picture']) && !empty($_FILES)){(uploadImage($_FILES['image'])} ;?>   

function uploadImage($image)
{
    $id = intval($_GET['id']);
    $size = 75; // the thumbnail height

    $filedir = '../img/products/'; // the directory for the original image
    $thumbdir = '../img/products/thumbs/'; // the directory for the thumbnail image
    $prefix = 'small_'; // the prefix to be added to the original name

    $maxfile = '2000000';
    $mode = '0666';

    $userfile_name = $image['name'];
    $userfile_tmp = $image['tmp_name'];
    $userfile_size = $image['size'];
    $userfile_type = $image['type'];

    if (isset($image['name'])) 
    {
        $prod_img = $filedir.$userfile_name;
        $url = strstr($userfile_name, '.', true);
        $type = strstr($userfile_name, '.');


        $prod_img_thumb = $thumbdir.$prefix.$userfile_name;
        move_uploaded_file($userfile_tmp, $prod_img);
        chmod ($prod_img, octdec($mode));

        $sizes = getimagesize($prod_img);
        $width = $size[0];
        $height = $size[1];
        if($width > $height) $biggestSide = $width;
        else $biggestSide = $height;

        //The crop size will be half that of the largest side
        $cropPercent = 1;
        $cropWidth   = $biggestSide*$cropPercent;
        $cropHeight  = $biggestSide*$cropPercent;

        //getting the top left coordinate
        $c1 = array("x"=>($width-$cropWidth)/2, "y"=>($height-$cropHeight)/2);

        $aspect_ratio = $sizes[1]/$sizes[0]; 

        if ($sizes[1] <= $size)
        {
            $new_width = $sizes[0];
            $new_height = $sizes[1];
        }else{
            $new_height = $size;
            $new_width = abs($new_height/$aspect_ratio);
        }

        $destimg=ImageCreateTrueColor($new_width,$new_height)
            or die('Problem In Creating image');
        $srcimg=ImageCreateFromJPEG($prod_img)
            or die('Problem In opening Source Image');
        if(function_exists('imagecopyresampled'))
        {
            imagecopyresampled($destimg,$srcimg,0,0,$c1['x'],$c1['y'],$new_width,$new_height,ImageSX($srcimg),ImageSY($srcimg))
            or die('Problem In resizing');
        }else{
            Imagecopyresized($destimg,$srcimg,0,0,0,0,$new_width,$new_height,ImageSX($srcimg),ImageSY($srcimg))
            or die('Problem In resizing');
        }
        ImageJPEG($destimg,$prod_img_thumb,90)
            or die('Problem In saving');
        imagedestroy($destimg);
        imagedestroy($srcimg);

        insertURL($id, $url, $type);

    }


}

Answer 1

您正在刷新哪个页面？ “您上传完成”的那个？按理说——这是上传的结果页面。刷新该页面后，您会看到常见的“此页面是 POST 的结果？重做 POST 吗？”键入警告，这将重新提交整个表单，包括文件。

为了防止刷新重新上传，您必须在表单处理代码完成后将用户重定向到其他地方。

<?php

if ($_SERVER['REQUEST_METHOD'] == 'POST') {

    // handle the upload

    if (/*form processed OK*/) {
       header("Location: successpage.php");
       exit();
    } else {
       // report any error conditions
    }
}

// show the form

?>

Answer 2

在此处阅读有关 POST-REDIRECT-GET 的信息：

http://en.wikipedia.org/wiki/发布/重定向/获取

Answer 3

当您刷新页面时，表单将重新发送，一切都会再次发生。使用表单时的一般规则是在脚本处理完提交的表单后将用户重定向到另一个页面。然后，即使他们重新加载页面，也不会重新提交任何内容，这样的问题就可以避免